What technical data does Eurohinca need to study the feasibility of a trenchless crossing or a microtunnel?

Q: What technical data does Eurohinca need to study the feasibility of a trenchless crossing or a microtunnel?

To study the feasibility of a trenchless crossing or a microtunnel, Eurohinca requires the complete geometry of the route (plan, profile, elevations and lengths), updated geotechnical information with SPT/CPT tests, water table and ground transitions, as well as the characteristics of the pipeline (diameter, material, operating pressure and tolerances). Also required are environmental constraints, easements, access and site restrictions, along with hydraulic requirements, client standards and applicable regulations. With these data, the safest and most efficient solution is defined depending on the method: microtunnel, HDD or Direct Pipe.

The evaluation of a trenchless crossing - either by microtunnel, HDD o Direct Pipe- requires a minimum set of technical data to ensure that the geotechnical, geometrical and constructive viability. Eurohinca analyzes each proposal integrating geology, hydraulics, environmental constraints and the client's operational requirements, in order to define the safest, most accurate and efficient solution.

In order to prepare a preliminary study or a technical offer, the following information is essential:

1. Geometry of the layout

Plan and profile with start and end coordinates.
Total length of the crossing and minimum coverages available.
Space for attack and reception wells, access and implementation areas.
Required bending radii and functional slopes (especially in gravity collectors).

2. Geotechnical characterization

Borings and tests: SPT, CPT, granulometries, Atterberg limits, RQD in case of rock.
Water table, The soil is permeable, permeability and the presence of granular materials susceptible to loss of lift.
Identification of terrain transitions (soft → hard, cohesive → granular).
Design parameters for shield type (EPB or hydroshield).

Planned piping

Outside/inside diameter and thickness.
Material (HRPV, concrete, ductile iron, steel).
Operating pressure and sealing requirements or certifications.
Admitted pipe lengths and geometric tolerances.

A detailed introduction to this process can be found at what is pipe jacking and how is it applied in subway projects?, where the basic design and execution parameters are explained.

4. Environmental conditions and easements

Existing infrastructure: roads, railways, pipelines, medium/high voltage cables.
Occupancy limitations, traffic conditions, access or deadlines.
Environmental or maritime conditions in case of outfalls.

5. Operating requirements and customer regulations

Utility's internal standards or EPC.
Hydraulic conditions (design Q, gradient, maximum pressure).
Need for CCTV inspection or specific final tests.
Load, tightness or differential pressure tests.

When any of these elements is not defined, Eurohinca can collaborate in the pre-engineering phase, The following table provides an overview of these applications, recommending alternatives or completing the necessary technical information. An overview of these applications can be found at terrestrial and subway applications, with real cases of crossings under roads, utilities or port areas.